Two people have succumbed to Kyasanur Forest Disease (KFD), commonly known as monkey fever, in Karnataka this year, prompting state health department officials to hold meetings and review the preparedness to tackle the spread of the viral infection.
The first death due to the infection was reported in Hosanagar taluk of Shivamogga district on January 8, wherein an 18-year-old girl succumbed to the virus. The second fatality was reported at Manipal in Udupi district when a 79-year-old man from Sringeri taluk in Chikkamagaluru died in a private hospital.
So far, the state has witnessed 49 positive cases of monkey fever with a maximum of 34 cases being reported in Uttara Kannada district, followed by 12 in Shivamogga and the remaining three in Chikkamagaluru district.
What is KFD or Monkey Fever?
Kyasanur Forest disease (KFD) is caused by the Kyasanur Forest disease virus (KFDV), a member of the virus family Flaviviridae. KFDV was identified in 1957 when it was isolated from a sick monkey from the Kyasanur Forest in Karnataka. Since then, between 400-500 humans cases per year have been reported.
The estimated case-fatality rate for KFD is from 3% to 5% .
How does the infection spread?
Transmission to humans may occur after a tick bite or contact with an infected animal, most importantly a sick or recently dead monkey. No person-to-person transmission has been established yet.
Large animals such as goats, cows, and sheep may become infected with KFD but play a limited role in the transmission of the disease. Furthermore, there is no evidence of transmission of the disease via unpasteurized milk of any of these animals.
What are the signs and symptoms?
After an incubation period of 3-8 days, the symptoms of KFD begin with chills, fever, and headache. Severe muscle pain with vomiting, gastrointestinal symptoms and bleeding problems may occur 3-4 days after the onset of initial symptoms. Patients may experience abnormally low blood pressure, and low platelet, red blood cell, and white blood cell counts.
After 1-2 weeks of symptoms, some patients recover without complication. However, the illness is biphasic for a subset of patients who experience a second wave of symptoms at the beginning of the third week. These symptoms include fever and signs of neurological manifestations, such as severe headache, mental disturbances, tremors, and vision deficits.
When can the infection be diagnosed?
Diagnosis can be made in the early stage of illness by molecular detection by PCR or virus isolation from blood. Later, serologic testing using enzyme-linked immunosorbent serologic assay (ELISA) can be performed.
What is the treatment?
There is no specific treatment for KFD, but early hospitalisation and supportive therapy is important. Supportive therapy includes maintenance of hydration and usual precautions for patients with bleeding disorders.
How can the disease be prevented?
A vaccine is available for KFD and is used in endemic areas of India. Additional preventative measures include insect repellents and wearing protective clothing in areas where ticks are endemic.
